1 files changed, 35 insertions, 0 deletions
diff --git a/examples/prompts/input-validation.py b/examples/prompts/input-validation.py
new file mode 100755
index 0000000..d8bd3ee
--- /dev/null
+++ b/examples/prompts/input-validation.py
@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+"""
+Simple example of input validation.
+"""
+from prompt_toolkit import prompt
+from prompt_toolkit.validation import Validator
+
+
+def is_valid_email(text):
+    return "@" in text
+
+
+validator = Validator.from_callable(
+    is_valid_email,
+    error_message="Not a valid e-mail address (Does not contain an @).",
+    move_cursor_to_end=True,
+)
+
+
+def main():
+    # Validate when pressing ENTER.
+    text = prompt(
+        "Enter e-mail address: ", validator=validator, validate_while_typing=False
+    )
+    print("You said: %s" % text)
+
+    # While typing
+    text = prompt(
+        "Enter e-mail address: ", validator=validator, validate_while_typing=True
+    )
+    print("You said: %s" % text)
+
+
+if __name__ == "__main__":
+    main()